The quick read
- For a calendar lookup, require a date range and specify the timezone.
- Validate inputs even when they look well formed.
A structured request
A tool has a name, a description and an input schema. The model can propose using that tool with particular arguments. Application code validates the request, performs the operation and returns a result. The model can then use that result in its next response.
Design the interface around the task
For a calendar lookup, require a date range and specify the timezone. Return an explicit empty result when no events match. Do not force the model to infer success from a vague message. Separate read-only lookups from actions that create, change or delete records, because their review requirements differ.
Handle the awkward cases
Validate inputs even when they look well formed. Make retries safe so an interrupted request does not create duplicate records. Return useful errors for expired access, missing fields and unavailable services. Test what happens when a tool succeeds but the final model response fails. A good tool interface turns an uncertain language request into an inspectable software operation, with evidence of what actually happened.
Sources & notes
AI-assisted editorial content checked against the linked sources.
Sources reviewed for the September 2026 launch edition.